FIGS. 1 and 2 show conventional read-after-write magnetic heads for magnetic tape apparatuses of the multi-track serpentine recording type in which a recording tape having a plurality of recording tracks is run backward and forward to sequentially record or reproduce information onto or from the tape.
In the conventional read-after-write magnetic head shown in FIG. 1, a first reading element Ra and a first writing element Wa are provided for one recording track a second writing element Wb and a second reading element Rb are provided for another recording track and are positionally related to each other in a reverse relationship relative to the first reading element RA and the first writing element WA, and an erasing element E extends over both the recording tracks.
In another conventional read-after-write magnetic head shown in FIG. 2, a first writing element Wa, a reading element R and a second writing element Wb are provided in that order for a recording track, and an erasing element E extends over a plurality of recording tracks.
Each of the conventional read-after-write magnetic heads is fixedly or movably attached in the direction of the width of the recording track, and performs small-width recording and large-width reproduction or large-width recording and small-width reproduction in order to secure a margin to avoid going off the recording track.
Since each of the elements of the conventional read-after-write magnetic heads is exclusively used for recording, reproduction or erasure at least three of the elements are needed for multi-track serpentine recording. Besides, the conventional magnetic head shown in FIG. 1 has three gapped portions which come into contact with the recording track of the recording tape, and the other conventional magnetic head shown in FIG. 2 has four gapped portions which come into contact with the recording track of the tape. For that reason, the number of elements of each of the conventional magnetic heads is relatively large, and the heads are disadvantageous in providing a good contact with the recording tape.
A recording tape having a width of 1/4 inch and 24 recording tracks therein has recently been used to perform recording and reproduction. Since the width of each of the tracks is as small as 0.229 mm, the conventional magnetic heads are likely to go off the track at the time of reproduction. In order to prevent the magnetic head from going off the track at the time of reproduction, it is required to enable automatic tracking at the time of reproduction in both the forward and backward directions of running of the tape. However, it is difficult to enable the automatic tracking with the conventional magnetic heads.